Back lighted signs and displays are commonly used both indoors and outdoors in connection with many commercial operations. Typically, such a sign or display comprises an enclosure having an opaque back panel mounting one or more light fixtures, and a front panel having a cutout window mounting a transparent or semi-transparent panel carrying a message display. In some cases, the message or display is applied to a translucid banner mounted behind the transparent panel. It is sometimes desirable to change the message or display which necessitates the replacement of the front panel or of the translucid banner. Examples of this type of display can be found in most fast food establishments where menus are presented by large back lighted displays mounted above the ordering counter. As available breakfast, lunch time, and evening menus may differ, those displays must be impractically very large to accommodate all menus, or their display banners must be replaced three times a day.
Prior attempts at resolving the aforesaid problems by means of hand-powered banner moving mechanisms have resulted in complex structures that are prone to jamming.
The invention results from attempts to develop a practical and inexpensive means and manners to retrofit display devices of the prior art into a self-powered and quickly updatable display system.